package com.myway.components.ehic.util;

import java.io.UnsupportedEncodingException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;


/**
 * 类名称：DESSignUtil <br/>
 * 类描述：DES加密工具 <br/>
 * 创建时间：2016年3月3日 下午6:41:48 <br/>
 * @author 张涛
 * @version V1.0
 */
public class DESSignUtil {
	
    /**
     * 名称：decrypt <br/>
     * 描述：解密 <br/>
     * @param message
     * @param key
     * @return
     * @throws Exception
     */
    public static String decrypt(String message,String key) throws Exception {

        byte[] bytesrc = convertHexString(message);
        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
        DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
        IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
        cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
        byte[] retByte = cipher.doFinal(bytesrc);
        return new String(retByte);
    }

    
    /**
     * 名称：encrypt <br/>
     * 描述：加密 <br/>
     * @param message
     * @return
     * @throws UnsupportedEncodingException 
     * @throws InvalidKeyException 
     * @throws NoSuchPaddingException 
     * @throws NoSuchAlgorithmException 
     * @throws InvalidKeySpecException 
     * @throws InvalidAlgorithmParameterException 
     * @throws BadPaddingException 
     * @throws IllegalBlockSizeException 
     * @throws Exception
     */
    public static String encrypt(String message,String key) throws Exception{
        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
        DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
        IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
        cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);
        byte[] doFinal = cipher.doFinal(message.getBytes("UTF-8"));
        return toHexString(doFinal);
    }

    public static byte[] convertHexString(String ss) {
        byte digest[] = new byte[ss.length() / 2];
        for (int i = 0; i < digest.length; i++) {
            String byteString = ss.substring(2 * i, 2 * i + 2);
            int byteValue = Integer.parseInt(byteString, 16);
            digest[i] = (byte) byteValue;
        }

        return digest;
    }

    public static String toHexString(byte b[]) {
        StringBuffer hexString = new StringBuffer();
        for (int i = 0; i < b.length; i++) {
            String plainText = Integer.toHexString(0xff & b[i]);
            if (plainText.length() < 2)
                plainText = "0" + plainText;
            hexString.append(plainText);
        }

        return hexString.toString();
    }

}